parenchyma

n.

1650s, Modern Latin, from Greek parenkhyma "something poured in beside," from para- "beside" (see para- (1)) + enkhyma "infusion," from en- "in" + khein "to pour" (see found (v.2)). In ancient physiology, the stuff that was supposed to make up the liver, lungs, etc., which was believed to be formed from blood strained through the capillaries and congealed.

(pə-rěng'kə-mə) The basic tissue of plants, consisting of cells with thin cellulose walls. The cortex and pith of the stem, the internal layers of leaves, and the soft parts of fruits are made of parenchyma. In contrast to sclerenchyma cells, parenchyma cells remain alive at maturity. They perform various functions, such as water storage, replacement of damaged tissue, and physical support of plant structures. Chloroplasts, the organelles in which photosynthesis takes place, are found in parenchyma cells. Compare collenchyma, sclerenchyma.